The present invention pertains to tool drivers and holders for rotary tools, and more particularly to a new and improved tool driver suitable for driving acetabular reamer cups and patella cutters and other surgical tools of any size which is easily cleaned and held and guided to rotate in true concentricity with the tool driver.
Patella cutters and acetabular reamer cups are surgical tools which are used in surgery for the insertion of artificial joints. Acetabular reamer cups are used to cut hemispherical cavities in pelvis bones for the insertion of artificial hip joints. Patella cutters are used to shape the underside of the patella or knee cap during knee replacement surgery. Patella cutters have a complex arrangement of precisely shaped cutting edges spirally arranged around the axis of rotation for cutting the patella. Acetabular reamer cups have a complex arrangement of cutting edges spirally arranged on a spherical surface around the axis of rotation of the cup. Both acetabular reamers and patella cutters perform better when rotated precisely about the axis around which these cutting edges are positioned by design. Additionally, precise tolerances cannot be achieved without precise axial rotation as designed.
It is therefore highly desirable to provide a new and improved tool driver. It is also highly desirable to provide a new and improved tool driver which can be used with acetabular reamer cups, patella cutters and like rotary tools. It is also highly desirable to provide a new and improved tool driver by which rotary tools may be driven about the tool driver's longitudinal axis with preciseness such that all of the cutting edges of the rotary tool function as designed.
Acetabular reamer cups also come in a full range of sizes. These sizes range from about 36 millimeters in diameter to about 72 millimeters in diameter. In the past, a specific tool driver could only be used with one or few of the sizes of available acetabular reamer cups. Thus, in any operating room there had to be several tool drivers for acetabular reamer cups. It is therefore also highly desirable to provide a new and improved tool driver by which acetabular reamer cups and patella cutters of all sizes can be driven.
Unique to some knee surgery and some hip operations is the utilization of milled bone, tissue and debris as filler to be placed between the artificial insert and the body to assist the healing process. Thus, acetabular reamer cups and patella cutters are mounted on tool drivers in a manner to collect such debris for such use. It is therefore, also highly desirable to provide a new and improved tool driver on which the rotary tools of the type which collect milled bone tissue and other debris for use as filler can be used.
In all surgery utilizing rotary tools, rotary tools such as driven by rotary tool drivers must be separable from their tool drivers to replace or sharpen as required. It may also be necessary to change tools during an operation, thus, both the rotary tools and the tool drivers must at times be cleaned, sterilized and reused. Thus, it is therefore also highly desirable to provide a new and improved tool driver which can be easily cleaned, sterilized and reused.
Some previous tool drivers grip the tool utilizing opposed pins, flanges and slots, or opposed spring loaded ball catches, or other such devices. These devices represent a problem in that the catches tend to trap dried blood and other debris which are very difficult to remove during a cleaning process. It is therefore also highly desirable to provide a new and improved tool driver which is simple in construction, easy to use and does not have opposed pins, flanges, slots and other devices in which to catch debris and render the tool driver difficult to clean, sterilize and reuse.
An additional problem is that unless tolerances of tools and tool drivers are made very close, at a greatly increased cost, there is considerable free play between the tool and the tool driver. This increased play increases the wear of the cutting edges, makes more difficult the positioning of the tool, renders the tool useless for holding close tolerances, requires the tool not to cut as designed, and there is no possibility of utilizing the rotary tool spinning precisely about its axis as designed. It is therefore, also highly desirable to provide a new and improved tool driver which allows the rotary tool to be utilized spinning precisely about its axis, as designed.
It is also highly desirable to provide a new and improved tool driver in which close tolerances can be held.
Finally, it is highly desirable to provide a new and improved tool driver which has all of the above desired features.